Driving in your car with a constant speed v, you encounter a bump in the road that has a circular cross section, as indicated in the figure . The radius of curvature of the bump is 35m At what speed must you go over the bump if people in your car are to feel weightless?pic:
Water has the atoms of oxygen and hydrogen joined together, so they are no longer the substance of oxygen or hydrogen. They now share electrons and are joined as one. They are H2O.
Oxygen is *NOT* a combustible gas. It supports combustion and is required for combustion but is not itself combustible. Hydrogen combines with oxygen (burns) to form water which as we all know is not combustible.
When elements combine to form a compound (such as water) the compound has completely different chemical properties from the original elements. Water smothers a fire by removing any gaseous oxygen from reaching the flames (oxygen itself doesn't burn, but fire requires oxygen to keep burning). Its like ordinary table salt - sodium and chlorine. Sodium reacts violently with water, and chlorine is a poisonous gas. But when in a compound they are an important component of most life on Earth (and make the potatoes taste good).
Oh! I tried to walk up the stairs with a giant cardboard box on my head once and I ended up hitting it on the side of the stairway and I fell down the stairs backwards.with the cardboard box still on my head :( So I'd have to agree with you on that one lol.
Oxygen and hydrogen are gases. Water may be a mixture of both, but water is a liquid. Liquids and gases have very different properties, and one of the main properties of water is that it is damp and wet. A fire needs three things to burn: a spark, fuel, and oxygen. When one of these three is compensated, the fire will usually go out. Dousing a fire with water makes the fuel harder to burn, and also may put out the spark.
